1. Field of the Invention
The present invention is related to a lavatory, and more particularly to a tank valve for a lavatory.
2. Description of Related Art
Referring to FIGS. 6 and 7, in a lavatory tank (40), a conventional tank valve (50) is pivotally mounted on an overflow tube (42) by a pair of arms (54). The tank valve (50) has a flange (51) formed at a top thereof, and an ear (52) is formed on the flange (51). A lift line (53) is attached in the ear (52) and connected with a lift arm (45). A hollow semi-spherical plug (55) is formed at a bottom of the tank valve (50) for plugging a water outlet (41).
The conventional valve (50) is generally made of rubber or plastic with a low density. When a user pulls up the lift line (53), the valve (50) is pivoted up about the overflow tube (42) to open the outlet (41), and water in the tank (40) flows out from the outlet (41) and flushes the bowl (not shown or numbered).
Because the plug (55) is hollow and the valve (50) has a density lower than that of water, the valve (50) floats in the water to open the outlet (41) until a surface of the water is below the valve (50). Thus, unless all of the water in the tank flows out, the valve (50) cannot be pivoted downwards to plug the outlet (41) again. If flushing the bowl does not need so much water, as in after a child""s urination, however, the user cannot control an out-flow capacity of water, and thus a lot of water is wasted.
Furthermore, early in the stage of water flowing in the tank (40), the flange (51) and the plug (55) cannot tightly close the outlet (41) because of the buoyancy exerting thereon. Water may leak out from gaps between the valve (50) and the outlet (41). When water in the tank reaches a certain level, under the pressure of the water the valve (50) then can tightly close the outlet (41). After a long time of use in water, the valve (50) will be hardened and the flange (51) may be deformed, so that the outlet (41) cannot be tightly closed and water will be leaked out too.
Furthermore, the ear (51) is often destroyed after a certain amount of use, and the lift line (53) is disengaged from the valve (50). Thus, the valve (50) must be replaced.
Therefore, the invention provides an improved a tank valve to mitigate and/or obviate the aforementioned problems.
The main objective of the invention is to provide a tank valve by which a user can control an out-flow capacity of water.
Another objective of the invention is to provide a tank valve which can immediately close an outlet of the tank when the user releases a handle.
A further objective of the invention is to provide a tank valve which has a long using life.